Magnetic Resonance Imaging (MRI) scans of women who were diagnosed
with cancer in one breast detected over 90 percent of cancers in
the other breast that were missed by mammography and clinical breast
exam at initial diagnosis, according to a new study. Given the
established rates of mammography and clinical breast exams for
detecting cancer in the opposite, or contralateral breast, adding
an MRI scan to the diagnostic evaluation effectively doubled the
number of cancers immediately found in these women. The American
College of Radiology Imaging Network (ACRIN) study, supported by
the National Cancer Institute (NCI), part of the National Institutes
of Health (NIH), appears in the March 29, 2007 issue of the New
England Journal of Medicine.*

“One in ten women diagnosed with cancer in one breast will develop
the disease in the opposite breast. Having a better technique to
find these cancers as early as possible will increase the chances
of successful treatment,” said NIH Director Elias A. Zerhouni,
M.D.

The ACRIN trial was designed to determine whether the use of MRI
could improve upon clinical breast exam and mammography in detecting
breast cancer in the opposite breast at the time of the initial
breast cancer diagnosis. The study recruited 1,007 women from 25
institutions who had a recent diagnosis of cancer in one breast.
969 women completed the study, which began in April 2003. All of
the women enrolled had a negative mammogram and negative clinical
breast exam of the opposite breast within 90 days prior to the
MRI. Of the 33 contralateral breast cancers diagnosed in the study,
30 cancers, or 91 percent, were diagnosed as a result of MRI. Researchers
found that the added benefit of MRI was consistent, regardless
of a woman’s cancer type, age, or breast density.

“This study gives us a clearer indication that if an MRI of the
opposite breast is negative, women diagnosed with cancer in only
one breast can more confidently opt against having a double, or
bilateral, mastectomy,” said NCI Director John E. Niederhuber,
M.D.

“We can now identify the vast majority of contralateral cancers
at the time of a woman’s initial breast cancer diagnosis,” said
Constance Lehman, M.D., Ph.D., principal investigator of the ACRIN
Breast MRI Trial, professor of radiology and director of breast
imaging at the University of Washington and Seattle Cancer Care
Alliance. “This means that instead of those women having another
cancer diagnosis years after their initial treatment, we can diagnose
and treat those opposite breast cancers at the time of the initial
diagnosis.”

Researchers are hopeful that with breast MRI’s strong ability
to predict the absence of a tumor, they can avoid some unnecessary
mastectomies and provide women with more reassurance that the breast
is disease free. “Although no imaging tool is perfect, if the MRI
is negative, the chance of cancer in that breast is extremely low.
A potential outcome that we would be delighted to see is fewer
unnecessary bilateral mastectomies,” said Lehman.

Researchers are optimistic that there may be long-term savings
to patients, and to the health care system, due to MRI’s ability
to detect cancer in both breasts prior to therapy — which
may result in fewer rounds of chemotherapy and breast surgeries.

Constantine Gatsonis, Ph.D., the study’s statistician and director
of Brown University’s Center for Statistical Sciences, Providence,
RI, said, "The size and scope of this study — which followed
nearly a thousand women receiving care in a variety of medical
settings — means that its findings are definitive and broadly
applicable. Women can be assured that a negative MRI means that
their chances of having a second cancer diagnosed within a year
is miniscule.”

For most women, the fear of a second cancer diagnosis is quite
high. The researchers are hoping that breast MRI can improve a
woman’s quality of life both at the time of her diagnosis and the
years following.

In the United States, breast cancer is the most frequent newly
diagnosed non-skin cancer in women, and the second leading cause
of cancer-related death. An estimated 178,480 women will be diagnosed
with breast cancer and an estimated 40,460 women will die of the
disease in the U.S. in 2007.

ACRIN is an NCI-sponsored and funded clinical trials cooperative
group made up of investigators from over 100 academic and community-based
facilities in the United States, as well as several abroad. ACRIN’s
mission is to develop information through clinical trials of diagnostic
imaging and image-guided therapeutic procedures that will result
in the earlier diagnosis of cancer, allay the concerns of those
who do not have cancer, and increase the length and improve the
quality of life for cancer patients. ACRIN administration is headquartered
at the Philadelphia office of the American College of Radiology
and is under the leadership of Network Chair Bruce J. Hillman,
MD, and Constantine Gatsonis, Ph.D. the Network Statistician. The
ACRIN Biostatistics Center is located at Brown University in Providence,
RI.

The American College of Radiology (ACR) is a national professional
organization serving more than 32,000 diagnostic radiologists,
radiation oncologists, interventional radiologists, nuclear medicine
physicians, and medical physicists, with programs focusing on the
practice of radiology and the delivery of comprehensive health
care services. Further information on the ACR can be found at www.acr.org.

For more information about cancer, visit http://www.cancer.gov,
or call NCI's Cancer Information Service at 1-800-4 CANCER.

The National Institutes of Health (NIH) — The Nation's
Medical Research Agency — includes 27 Institutes and
Centers and is a component of the U.S. Department of Health and
Human Services. It is the primary federal agency for conducting
and supporting basic, clinical and translational medical research,
and it investigates the causes, treatments, and cures for both
common and rare diseases. For more information about NIH and
its programs, visit www.nih.gov.